PLANT INTRODUCTION NOTES. 19 



Transvaal Department of Agriculture, 

 ( rovernment buildings, 

 Pretoria, February .'/, 190-i. 

 Sir: I am sending you per same p<»t a box containing a weed forwarded to me for 

 identification. As we are at present without a botanist, I trust you will kindly help 

 mi' in the matter. * * * For your fuller information \ inclose the letter which 

 accompanied the specimen. 



I have the honor t<> be, sir, your obedient servant, 



R. A. Davis. 

 Professor MacOwan, Cape Town. 



[Inclosure.] 



Sandba( ii, Amsterdam P. 0., February 15, 190S. 

 Sik: I am sending you by this post a box containing a weed which is very preva- 

 lent (Hi this farm. The Dutch call it "Rooi-blot m." When it appears among mealies 

 it immediately kills the mealies. 1 have a field of over 40 acres which had a first- 

 clas.s crop of mealies three weeks ago; since then this "Rooi-iil <<>„,'' has appeared, 

 and I am doubtful if \ shall get live bags off the whole field. The Dutch say there 

 is no cure for it, and nothing can lie done to eradicate it; but I can not find out 



whether anything has be* n tried. Will you he g 1 enough to inquire if any known 



cure exists? It is said that "Rooi-bloem " only affects mealies. I have been trying 

 to get oats for sowing in April, but can not gel any "Africander" outs. 

 Yours, faithfully, 



( i. S. Lkslie. 

 Secretary Land Board, Pretoria. 



Cape <Iuverxmext Herbarium, 



Cape Tovm, February 28, 190S. 



My dear Sir: I am in receipt of your letter of the 24th instant respecting a weed 

 doing mischief in mealie crop-, and of the sample belonging thereto. 



The plant is a semiparasite, Striga coccinea Bth., and is not infrequent on our 

 eastern frontier. Its habits resemble those of Rhinanthus crista-galli L., the "yellow 

 nitric" and Melampyrum prdten&e L., in that it is aide to live easily on its own roots 

 like other normal plants, but also to attach itself to those of more succulent neigh- 

 bors and draw surreptitiously upon their food material. It will work when it must, 

 hut prefers the easier life of a predatory parasitism. 



As to extirpation of this showy interloper, advise your correspondent to give up 

 for the present the culture of cereals upon the acreage infested with Striga, so that 

 the parasite shall find no host to receive it, and perseveringly plow and cross 

 plow, following with the harrow to get the weeds into heaps for drying and burn- 

 ing. A crop of totally different character, such as lucerne, for instance, would be 

 best. But if local conditions do not allow of this, a double cropping with rape, to 

 be grown on till fit for stock food, fed off, and then turned in to make way for the 

 second crop suggests itself. The object is to give no chance to the Striga to renew 

 its parasitism. The seed of the Striga is small and tenacious of life, hence the 

 repeated working of the soil is important. Also it would be well to use kraal manure 

 in place of stable dung. It is astonishing what a number of weed seeds pass through 

 the intestinal tract of the horse, and since we very rarely keep his contribution to 

 the fertility of the farm long enough to insure their being killed out by a proper 

 rotting down, we innocently sow a crop of weeds along with the manure. This is 

 the secret of the spread of "zuuring" far and wide. 



